Signaling circuit



Jan. 13, 1925. 1,523,037

D. A. QUARLES SLGNALING CIRCUIT Filed Oct. 26, 1922 cuits.

4 ever signals are received 86 circuit includes the o Patented Jan. 13, 1925,

i UNITED STATES 1,523,037 PATENT OFFICE.

DONALD A. QUARLES, OF ENGLEWOOD, NEW JERSEY, AS SIGNOR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, 011' NEW YORK, N. Y A. CORPORATION OF NEW YORK.

SIGNALING CIRCUIT.

To all whom it may concern:

Be it known that I, DONALD A. QUARLBS, uvcitizen of the United States, residing at Englewood, in the county of Bergen, State a of New Jersey, have invented certain new and useful Improvements in Signaling Circuits, of which the following is a full, clear, concise, and exact description.

This invention relates to signaling cir- Anobject or this invention is to provide an anti-side-tone transmitting and receiving set for a signaling line. i

Another obiect of this invention is to providea high iency operators transmitting and receiving set for talking and monitor- 1 ing over tele hone lines.

Another 0 ject of this invention is to rovide an operators talking and-monitor- 2 .v mg set fora repeater station which may be associated with the repeater without danger of causing the repeater to sing j his invention is hereinafter described in detail in connection with-a telephone repeater station in which two-wayam lified trans- 1 mission is obtained throu h the intermediary of a three-windin transformer arranged inthe form of a eat/stone bridge network to prevent a local circulation of power whenassociated line sections. The equivalent of a' three-wire circuitis employed in asso ciating the operators set with the repeater circuit. The middle branch of the three eratorsreceiver, while the one side wire an the middle wire includes a monitoring winding on the threewinding transformer of one line section and the other side wire and the iddle wire includes a similar winding ofthe three-windtransformer associated with the other line section to which the repeater is conled. The transmitter of the operators set is connected so as to impress the currents from the transmitter serially upon the two outside branches. 7 The drawing represents this invention ap lied to a 22 type repeater circuit.

' e si aling arrangement comprises two line sections 4 and 25- coupled in the wellknown manner by a 22 type repeater. circuit to give amp nals in both direction: between the two line sections. Block 6 indicates a suitable repester or amplifier which may be of the from either of the transmission for the sig-' Application filed October 26, 1922. Serial No. 596,928.

vacuum tube three-electrode t pc for receivin signals from line 4 and impressing them 1n amplified form upon line 5. Blocks 7 indicates a repeater for amplifying signals to be transmitted in the opposite direction. The inputterminals of repeater 6 are coupled to the mid points of windings8and 9 while the oppgsite terminals of repeater 6 are coupled to the .winding 10 of an output transformer which has its secon dary winding in series with line 5. Similarly the input terminals of repeater 7 are connected to the mid points of line windings 11 and 12 while its output terminals areeconnected to winding- 13 which is inductively associated with winding 8-and 9. Lines 4 and 5 are properly balanced by artificial lines marked 7 N. This. arrangement insures that none of the output energy of repeater 7 will be impressed upon the input terminals of repeater 6 and that none of the output energy of repeater'6 will .be impressed upon the input terminals of re eater 7.

In order to provide a ta ing and monitoring circuit for the line sections interconnected by repeaters 6 and 7, this invention provides a-monitoring winding 14 asociated with the transformer of line 4 and a-monitoting winding 15 associated with the transformer of line 5, These monitoring windings are associated with the operators receiver 16 and transmitter 17 by the equivalent of a three wire circuit, winding 14 being included in series with one side wire-- 18 and middle wire 19 and the other wind. in" 15 being included in series with the, middle wire 19 and the other side wire 20.-

The operators receiver 16 is as shown connected in series with the middle wire 19. The.operators transmitter 17 is coupled to the three-wire circuit by a transformer 21 so arranged that the currents from the transmitter are impressed serially upon the outside branches 18 and 20 of the three-wire circuit. If equal impedances are included between points 22 and 23 and between points i 23 and 24 and fif monitoring \viniling"'14 is properly balanfied by monitoring winding 15, it follows i at none of 'the energy from transmitter 17' will beimpressed upon the receiver 16 since the point 23 for the trans mitted currents will be at the same otential as the comnion terminal of win ings 14.- and 15.

. With this arrangement, incoming signals "to sing is produced, since the energy transmitted through winding to the line, siniilar to the action of winding 10, produces.

no potential difierences upon the input ter minals of repeater 7 and winding 14, sunllar to'winding 13, will impress no potential differences upon the input terminals of repeater 16.

Another advantage of the arrangement just above described is that the monitoring windings 14 and 15 are so related that amlified signals from either the repeater 6 or 9 will not be fed back through the intermediary of the monitoring-windings. Due to the three-wire connection above described the amplified signals-from repeater 6 will induce potentials in windings 15 but -these tentials will not be impressed on winding. 14 due to'theiranti-side-tone relation. 'That is, potentials induced in windings 15 by the transmitter 17.- In other words, the transamplified signals from repeater 6 will cause. current to flow-through care 20, the winding oftransformer 21 from terminal 24 to ter-. minal 23, throu h receiver 16 andback to windings 15. T is current-will tend to divide at terminal23 and part'fiow through the transformer winding to terminal 22, through wire 18 and windings 14 back to windings 15. However, due to the induc-T tive relation of that portion of winding 21 between terminals 24 and 23 andthat portion between terminals 23 and 22,- a potential is set up in the latter-winding by the current flowin in the former winding which balances the e ectromotive force tending to cause the current to flowthrough the windings 14 andso current will flow only through the receiver 16xand through the former '21 with. the four impedances 14, 15, '16, and 17, which are connected to it, forms a biconjugate network. Similarly amplified signals from repeater 7 which will impress potentials u n windin 14 will not feed en- "ergy back t rough win ing 15 upon the in;

putterminals of repeater 7.

Still another advantage is that -no com- ,plex' artificial network 15 required, in obtaining the ant'i-side-tone features of the operator sset since one of the monitoring windings is balanced against the other. Furthermore none of the energy from the transmitter is lostin a balancing network such as is used in anti-side-tone substation circuits, but all of the energy from the transmitter is impressed on the two line sections through windings 13 and 15.

The invention claimed is:

1. A monitoring circuit for a telephone repeater" station employing balanced repeater coils. comprising monitoring -windin in ducti-i'ely associated with the line win ingS of said repeater coils, an operators substa-' tioft set compr sing a transmitter and a re--' ceiver, and connections from said substation set to each of a plurality of said monitoring windings for balancing the impedance'of one of said monitoring i'vindin against theimpedance of another of 'sa monitoring windings to render said substation set antl- -sidc-tone when transmitting from said transmitter. 4

.2. A signal system comprising two transmission lines, a two way repeatercircuit, a

network for balancing each of said lines, a

transformer .for associating one of said lines with one of said networks and said repeater circuit, a second transformer for associating the otherof said'lines with the second of said networks and said repeater circuits, an auxiliary winding mounted on each of said transformers, a substation set comprising a transmitter and .rreceiver and connections from said. substation set to said auxiliary windings for impressmgcurre'nts from said transmitter serially upon said windings while preventin side-tone in said receiver.

3. A monitoring circuit comprising two outside branches, a central conducting path, a monitoring transformer winding in one of saidoutside branches, a second, transformer winding in said other outside branch. means for inductively associating said windings with a signaling-line for monitoring 'pur poses, an impedance having saidoutsidebranches connected to different points thereof and having said central path con- 110.

nected to an intermediate point, a receivingdevice and a transmitting device, one of said devices being connected in said central pat-h and the other of said devices coupled to said impedance.

4. In combination, two signaling lines, means for receiving signals from said lines, said lines being connected to said receiving means in substantially. conjugate-relation for preventing the transfer of signals from one of said-lines to the other of said lines through'said receiving means, and transmitting means for impressing signaling currents on said lines, said transmitting and receiving means being conjugate.

5. In combination, two signaling lines, two way repeating means interconnecting said lines, means for receivingsignals from said lines, said lines being connected to said receiving means in substantially conjugate relation for preventing the transfer of signals from one of said lines to the other of said lines through said receiving means.

6. In combination, two signaling lines, two way repeating means interconnecting said lines, means connected to said lines for receiving signals therefrom, said connections belng provided with means for preventing the transfer of signals from one of said lines to the other of said lines through said receiving means.

7. A monitoring circuit comprising two outside branches and a central conducting path, a monitoring transformer winding in one of said outside branches, a second transformer winding in said other outside branch, means for inductively associating said windings with a signaling line for monitoring purposes, a receiver connected in said central path, an impedance having said outside branches connected to different points thereof and having said central path connected to an intermediate point, and a transmitter coupled to said impedance.

8. In combination two line sections, a repeater for repeating signals between said line sections in one direction, a second repeater for repeating signals in the opposite direction, an output transformer for coupling the output of each repeater to one of the line sections, and comprising a winding in circuit with the repeater and a winding in circuit with the line sections, a third winding for each of saidtrans-formers, an operators substation set comprising a transmitter and a receiver, and connections between said third windings and said substation set for balancing the impedance of one of said third windings against the impedance of the other third winding for preventing side tone in said receiver.

9. In combination, two line sections, a re peater for repeating signals in one direction between said line" section, a second repeater for repeating signals in the opposite direction, an output transformer for each-of said repeaters comprising a winding in circuit with the repeater and a winding in circuit with the llne. section, a third winding on each of said transformers, a three Wire circuit comprising two outside branches and a central conducting path, one of said third windings being included in one outside branch, the other of said third windings being included in the other outside branch, a telephone receiver in said central path, a transmitter, and means for impressing currents from said transmitter serially upon said outside branches.

In witness whereof, I hereunto subscribe my name this'25th day of October A. 1)., 1922.

DONALD A. QUARLES. 

